Aircraft electric brake actuation system and method

Abstract

A system and method of controlling aircraft brakes in an aircraft that includes a brake pedal and an electric brake actuator. An aircraft operational state is determined and an application force that is supplied to the brake pedal is determined. When the determined aircraft operational state is a ground-idle state and the determined application force is greater than a set force magnitude, an actuator brake is moved to engage the electric brake actuator and the electric brake actuator is de-energized.

What is claimed is: 
     
       1. A method comprising:
 determining an aircraft operational state; 
 measuring an application force supplied to a brake pedal of an aircraft; and 
 moving an actuator brake to engage an electric brake actuator and de-energizing the electric brake actuator when (i) the determined aircraft operational state is a ground-idle state, wherein the ground-idle state is a state in which the aircraft is moving, and (ii) the measured application force is greater than a set force magnitude. 
 
     
     
       2. The method of  claim 1 , further comprising:
 disengaging the actuator brake and re-energizing the electric brake actuator when the application force is less than a reset force magnitude. 
 
     
     
       3. The method of  claim 1 , wherein determining the aircraft operational state comprises measuring aircraft wheel speed. 
     
     
       4. The method of  claim 1 , wherein determining the aircraft operational state comprises detecting that the aircraft is on a surface. 
     
     
       5. The method of  claim 1 , wherein the aircraft further includes an engine throttle, and wherein determining the aircraft operational state comprises determining an engine throttle position of the engine throttle. 
     
     
       6. The method of  claim 1 , wherein the ground-idle state is a state in which the aircraft is moving at less than a predetermined speed. 
     
     
       7. An electric brake control system for an aircraft, the electric brake control system comprising:
 an electric brake actuator configured to be controllably energized and, upon being controllably energized, to move to a brake position; 
 an actuator brake configured to move between an engage position, in which the actuator brake prevents movement of the electric brake actuator, and a disengage position, in which the actuator brake does not prevent movement of the electric brake actuator; and 
 a control circuit configured to receive one or more signals representative of aircraft operational state and one or more signals representative of a brake pedal application force, the control circuit being configured to, in response to the one or more signals representative of aircraft operational state and the one or more signals representative of a brake pedal application force, command the actuator brake to the engage position and to de-energize the electric brake actuator when the aircraft operational state is a ground-idle state and the application force is greater than a set force magnitude, wherein the ground-idle state is a state in which the aircraft is moving. 
 
     
     
       8. The system of  claim 7 , wherein the control circuit is further configured to command the actuator brake to the disengage position and re-energize the electric brake actuator when the brake pedal application force is less than a reset force magnitude. 
     
     
       9. The system of  claim 8 , wherein the control circuit comprises:
 an actuator control coupled to receive actuator commands and configured, in response thereto, to controllably energize the electric brake actuator; and 
 a brake control coupled to receive the one or more signals representative of aircraft operational state and the one or more signals representative of the brake pedal application force, the brake control being configured to, in response to the one or more signals representative of aircraft operational state and the one or more signals representative of the brake pedal application force:
 (i) supply the actuator commands to the actuator control, 
 (ii) selectively command the actuator brake to the engage position and the disengage position, and 
 (iii) selectively de-energize the electric brake actuator. 
 
 
     
     
       10. The system of  claim 7 , wherein the actuator brake is coupled to the electric brake actuator and, in the engage position, engages the electric brake actuator to maintain the electric brake actuator in the brake position. 
     
     
       11. The system of  claim 7 , wherein the one or more signals representative of aircraft operational state include one or more of:
 a sensor signal that indicates the aircraft is on a surface; 
 a wheel speed signal representative of aircraft wheel rotational speed; and 
 an engine throttle position signal representative of aircraft engine throttle position. 
 
     
     
       12. The system of  claim 11 , further comprising:
 a weight-on-wheels sensor configured to sense when the aircraft is on the surface and to supply the sensor signal to the control circuit; 
 a wheel speed sensor configured to sense the aircraft wheel rotational speed and to supply the wheel speed signal to the control circuit; 
 a throttle position sensor configured to sense the aircraft engine throttle position and supply the engine throttle position signal to the control circuit. 
 
     
     
       13. The electric brake control system of  claim 7 , wherein the ground-idle state is a state in which the aircraft is moving at less than a predetermined speed. 
     
     
       14. An electric brake control system for an aircraft, the electric brake control system comprising:
 a plurality of electric brake actuators, each electric brake actuator of the plurality of electric brake actuators being configured to be controllably energized and, upon being controllably energized, to move to a brake position; 
 a plurality of actuator brakes, each actuator brake of the plurality of actuator brakes being configured to move between an engage position, in which the actuator brake prevents movement of an electric brake actuator of the plurality of electric brake actuators, and a disengage position, in which the actuator brake does not prevent movement of the electric brake actuator; and 
 a control circuit coupled to receive one or more signals representative of a brake pedal application force and one or more signals representative of an aircraft operational state, the control circuit being configured to, in response to the one or more signals representative of the brake pedal application force and the one or more signals representative of the aircraft operational state:
 (i) determine the aircraft operational state, 
 (ii) determine the brake pedal application force supplied to the brake pedals, and 
 (iii) command the plurality of actuator brakes to the engage position and de-energize the electric brake actuators when that the aircraft operational state is a ground-idle state and the brake pedal application force is greater than a set force magnitude, wherein the ground-idle state is a state in which the aircraft is moving at less than a predetermined speed. 
 
 
     
     
       15. The system of  claim 14 , wherein the control circuit is further configured to command the actuator brakes to the disengage position and re-energize the electric brake actuators when the brake pedal application force is less than a reset force magnitude. 
     
     
       16. The system of  claim 15 , wherein the control circuit comprises:
 a plurality of actuator controls, each actuator control of the plurality of actuator controls being coupled to receive actuator commands and configured, in response thereto, to controllably energize the plurality of electric brake actuators to move to the brake position; and 
 a plurality of brake controls, each brake control of the plurality of brake controls being coupled to receive the one or more signals representative of an aircraft operational state and one or more signals representative of the brake pedal application force, each brake control being further configured to, in response to the one or more signals representative of aircraft operational state and the one or more signals representative of a brake pedal application force:
 (i) supply the actuator commands to the plurality of actuator controls, 
 (ii) selectively command the plurality of actuator brakes to the engage position and the disengage position, and 
 (iii) selectively de-energize the plurality of electric brake actuators. 
 
 
     
     
       17. The system of  claim 16 , wherein:
 the aircraft comprises at least a left landing gear and a landing gear wheel; 
 the landing gear wheel includes an inboard wheel and an outboard wheel; 
 at least one actuator brake of the plurality of actuator brakes and at least one electric brake actuator of the plurality of electric brake actuators are coupled to the inboard wheel; 
 at least one actuator brake of the plurality of actuator brakes and at least one electric brake actuator of the plurality of electric brake actuators are coupled to the outboard wheel; and 
 the plurality of actuator controls are configured so that the at least one actuator brake of the plurality of actuator brakes and the at least one electric brake actuator of the plurality of electric brake actuators coupled to the inboard wheel apply a brake force to a same brake stack. 
 
     
     
       18. The system of  claim 14 , wherein each actuator brake of the plurality of actuator brakes is coupled to an electric brake actuator of the plurality of electric brake actuators, and, in the engage position, engages the electric brake actuator to maintain the electric brake actuator in the brake position. 
     
     
       19. The system of  claim 14 , further comprising:
 a plurality of brake pedal sensors, each brake pedal sensor being configured to sense a brake pedal position and to transmit a position signal representative of the brake pedal position to the control circuit, 
 wherein the control circuit is configured to determine the brake pedal application force from the position signal. 
 
     
     
       20. The system of  claim 14 , further comprising:
 a plurality of aircraft state sensors, wherein each aircraft state sensor is configured to supply a signal representative of the aircraft operational state to the control circuit.